libcxx/memory/trivial_abi/{unique,weak}_ptr_ret.pass.cpp tests fail on 32-bit x86

[llvmbot]

Bugzilla Link	48939
Resolution	FIXED
Resolved on	Jun 04, 2021 20:36
Version	trunk
OS	Linux
Blocks	#48661
Attachments	Output of tests (.txt), sys-libs:libcxx-12.0.0_rc1:20210129-094954.log.xz
Reporter	LLVM Bugzilla Contributor
CC	@mkurdej,@hvdijk,@ldionne,@slacka,@tstellar
Fixed by commit(s)	73cdc75 f1b1151

Extended Description

I get the following two failures on 32-bit x86 (using amd64 multilib):

libc++ :: libcxx/memory/trivial_abi/unique_ptr_ret.pass.cpp
libc++ :: libcxx/memory/trivial_abi/weak_ptr_ret.pass.cpp

I'm attaching the full output of the tests. The errors seem to boil down to:

t.tmp.exe: /tmp/portage/sys-libs/libcxx-12.0.0_rc1/work/libcxx/test/libcxx/memory/trivial_abi/unique_ptr_ret.pass.cpp:49: int main(int, char *): Assertion `(void)&ret != local_addr' failed.

t.tmp.exe: /tmp/portage/sys-libs/libcxx-12.0.0_rc1/work/libcxx/test/libcxx/memory/trivial_abi/weak_ptr_ret.pass.cpp:55: int main(int, char *): Assertion `(void)&ret != local_addr' failed.

These tests pass on pure amd64.

[mkurdej]

These tests were added after release 11 (revision https://reviews.llvm.org/D82490, commit 76887bc) and, to the best of my knowledge, never passed on 32-bit x86.
Also, they're disabled on ARM32 (since commit f5e49bd):

#ifndef __arm__
  // On ARM32, structs larger than 4 bytes cannot be returned in registers.
  // Thus, weak_ptr will be passed indrectly even if it is trivial.
  assert((void*)&ret != local_addr);
#endif

IMO, this comment applies to 32-bit x86 as well.

Anyway, I don't think it should be a release blocker.

[tstellar]

This bug was not resolved in time for the 12.0.0 release, so it will have to wait for 12.0.1.

If you feel this is a high-priority bug that should be fixed for 12.0.0, please re-add release-12.0.0 to the Blocks field and add a comment explaining why this is high-priority.

[slacka]

I doubled checked and all libc++ tests pass on native 32-bit x86. Tested on openSUSE Tumbleweed i686.

[hvdijk]

I created https://reviews.llvm.org/D102359 to fix these, plus one more test.

[ldionne]

This should be fixed now (thanks Harald!):

commit 73cdc75
Author: Harald van Dijk harald@gigawatt.nl
Date: Mon May 31 12:36:57 2021 -0400

[libc++] [test] Fix a few tests for 32-bit x86

Fixes bug llvm/llvm-project#48283 .

Differential Revision: https://reviews.llvm.org/D102359

[hvdijk]

Thanks for committing! Reopening as this is marked for 12.0.1; Tom, do you want to cherry-pick this into the 12.x branch?

[tstellar]

Merged: f1b1151

[tstellar]

mentioned in issue #48661